Plate heat exchanger



FIG. 1 is a left side elevational view of a plate heat exchanger showing my new design, the right side being a mirror image;

FIG. 2 is a front elevational view thereof, the top being identical and the rear and bottom being a mirror image;

FIG. 3 is an enlarged fragmentary view of the plate as seen in circle 3 in FIG. 2. 

The ornamental design for a plate heat exchanger, as shown and described. 